Working vehicles such as riding lawn mowers have often included roll bar assemblies for protecting an operator during a rollover. Typically, such a roll bar assembly includes at least an upper roll bar portion which has two side members and a top member connecting between the side members. The side members of the upper roll bar portion are either fixed to the vehicle frame in a raised position or are pivotably mounted at least indirectly to the vehicle frame by pivot joints. When pivotably mounted, the pivot joints usually allow the upper roll bar portion to be secured in either a raised position for normal operations or a folded-back position for avoiding overhead obstacles. Typically, a working vehicle, such as riding lawn mowers is shipped to a dealer or buyer in a shipping crate. However, neither the raised position nor the folded-back position is suitable for shipping because at least a portion of a roll bar will extend outside a shipping crate. Accordingly, it is often necessary to remove at least the upper portion of a roll bar assembly for shipping. What is needed is a roll bar assembly which is arranged so that the upper portion does not have to be removed for shipping.